[Utilization of 4-chlorobenzoic acid by Arthrobacter globiformis]

A strain of Arthrobacter globiformis utilizing 4-chlorobenzoic acid as a sole source of carbon and energy was isolated by the method of enrichment cultures from vegetable garden soil near Moscow. The yield of released chlorine upon the utilization of 4-chlorobenzoic acid exceeded 96% of the theoretically possible one. Biotin stimulated noticeably the utilization of the acid. The concentration of 4-chlorobenzoic acid that apparently did not inhibit the growth of the isolated organism was within the range of 0.5-0.6 g per litre. The strain utilized a number of mono- and dihydroxybenzoic acids but not benzoic acid. This observation make possible that dehalogenization occurs at the first step of preparative metabolism. The oxidation of 4-chlorobenzoic acid, 4-hydroxybenzoic acid, protocatechuic acid and galactose by the cells grown on these compounds has been studied and shown that the oxidation system for 4-chlorobenzoic acid is an inducible one whereas that for 4-hydroxybenzoic and protocatechuic acids is a constitutive or a semiconstitutive one.